Okay, had to switch to desktop mode for this one, but: [ URL=" http://URL here" ]link text[ /URL ] without the spaces, of course.

It does suck on mobile. To be honest I always hit reply with quote on someone else's post to see how they did something if I can't figure it out. Haha. But make sure you are using brackets with these and not < or >. That's what threw me off at first.